The monitoring of the condition of elderly people in a home environment is indispensable if it is desired to lengthen the possibility of an aging population to manage in its home environment. Safety bracelet systems are in widespread use. Their weakness is that the user must wear the bracelet continuously and must be able to press the alarm button in an emergency. Bracelets that check the state of health also exist, but one of their problems is false alarms.
Prior art has also sought solutions in which a film that is of piezoelectric material is installed on the floor, which film registers pressure changes caused by movement on the surface of the floor. Also known to be used are sensors to be installed on the floor, or under it, that detect the presence and movements of people without a change in pressure by means of capacitive sensors.
The possibility of using videocameras, movement detectors that are based e.g. on detecting infrared light, or e.g. ultrasound sensors for monitoring the condition and state of elderly people is also presented in prior art.
The use of a dense near-field sensor field in detecting presence is presented in publication U.S. Pat. No. 6,407,556B1, among others.
The use of pressure sensors for detecting presence or movement is presented in publication U.S. Pat. No. 4,888,581A1, among others.
Known in the art are solutions for tracking a number of objects (multitarget tracking) and e.g. the linking of the type of the object to the object as a part of the tracking of the object is presented in publication U.S. Pat. No. 6,278,401B1.
The use of a near-field sensor that is to be installed in the floor and measuring an electrical connection for making observations is presented in publication W02005020171A1, among others.
Publication WO2009106685 describes a prior-art method and system for tracking objects that uses a dense sensor field.
Publication WO2012164169 describes a prior-art method and system for tracking objects based on ultrasound technology.
A drawback with prior-art observation systems and monitoring systems is that the sensors in the systems can be used for only one functionality, e.g. for monitoring the condition and/or state of elderly people.